I'm outgrowing my TTR-125L pretty fast, it's my first bike and I'm pretty new to the sport, but I'm a quick learner and am picking up new riding skills every day and such. I'm starting to feel that my bike is underpowered. I've heard of ways that the TTR-125's can be "uncorked." Today I was riding without the spark arrestor endcap and it seemed to make a noticeable difference in the power output. What are some other cheap (free?) and easy modifications that I can do to give my TTR a little more juice just to hold me off until I get my next bike (CRF230F or a YZ250F)
I heard about cutting out a piece of the air filter but I don't understand exactly how this is done. If someone could please explain that, along with anything else I can do that's not going to empty my bank account. Thanks,
Jake

dont cut out the airfilter unless u intend on getting a new bike..... you couldd take the top of your airbox.... and the metal mesh on your airfilter cage can be removed for better airflow and performance....

Cyber here is a link to the Air Box Mod this should explain it a little better. If it doesn't make sense pm me and I will explain it better. I have done it to my sons and it makes a difference. You may have to richen it as it might lean you out too much. Good luck hope this helps. The web site you are going to go to is all about TTRs so browse around at the other mods for more ideas. Credit where credit is due Blitz393 helped me with this. Thanks Blitz it works great. The fork shim mod will be next.

the fork shim mod worked great for me too, but that 40' double really doesnt care what you did, it will kill the TTRs suspension but, it helps. another thing i have heard for making more power out of the TTR, (or any four stroke bike) is to take the spark plug out, and draw a line on the ceramic coating where the open end of the plug gap is, and then use thin washers to screw in the plug into the head so that the open end of the gap is pointing towards the intake, so that combustion is better. i dont know if it makes any difference, but i did it anyway. :

I cut the airbox on my TTR125L like the TTR125L.com website said. It made a pretty good increase in power and acceleration. I want to know if I buy the BBR freeflow airfilter kit, will this help even more or will it even do anything at all since I cut my airbox? Also, would the BBR pipe (or any other pipe for that matter) help me out? What carb adjustments do I need to make. I found a screw on the carb but I think its idle speed, what adjustments should I do?

First off, get a service manual of some kind so you know what you have to do to replace JETS in the carb (that is the jetting part).

Next. Any pipe is better than stock for your bike. That TT-R site did some reviews on different pipes, if noise isn't an issue i would go for a Pro-Circuit T-4 (around 200-250 at http://www.BTOsports.com)

Finally i don't know what the BBR Freeflow airfilter kit is, but if you buy a UNI filter it comes with a better, more freeflowing cage, and the Filter element itself.

Ok I have a TTRL and everyone has told you well. I think what would work better than cutting the restrictor plate is cutting out the top of the air box.
If you remove the seat you will see a box with this thing that looks like a snorkel poking out. The reason thats there is for noise restriction since its a trail bike. For example take off the side cover off the air box and run the bike one time. It will sound and feel more powerful. For the suspension all you can really do is switch the forks to a 15-20wt. fork oil (20wt. may be stretching it), the rear shock is decent but is crying out for a stiffer spring, just set your sag at around 1.5-2 inches. Remove the cork from your exhaust after the airbox mod, then re jet to a 110 main with a 17.5 pilot jet. This outta be good for the limited budget.

thanks for all the help. i cut the air box lid about a month ago and yes it did make a pretty noticable difference. i thought it was fast... until i got my YZ250F two days ago. I know those 250f's are supposed to be pretty fast stock but I got mine already all tricked out and this thing really rips. The TTR is now my little brothers, and he's pretty happy about that coming off of an XR100. But not as happy as I am with the 250f. What great bikes, the TTR and the 250F. Yamaha really knows what they are doing. They can make a beginners bike thats easy to ride and handle and not too slow, and then they can make a 250 four stoke that absolutely RIPS. I'm impressed. Go yamaha